697 research outputs found

    Picard - an electrostatic particle in cell simulation code

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    This is a particle-in-cell plasma code 'picard' that was developed by Jesper Lindkvist and Herbert Gunell with start in 2016 using resources provided by the Swedish National Infrastructure for Computing (SNIC) at the High Performance Computing Center North (HPC2N), Umeå University, Sweden. Jesper Lindkvist was funded by the Swedish National Space Board (SNSB project 201/15) and Herbert Gunell by the Swedish National Space Agency (SNSA project 108/18). A paper based on the first version was published in A&A . The present version has been updated to include ionisation as a source of cometary ions, and hdf5 files are used for writing the output. The changes in this version were made by Herbert Gunell. The files included are: picard.tgz Package containing all source file, some matlab m-files that can be used for plotting of the results, and an input file that was used for a simulation that will be used in an upcoming publication by Herbert Gunell and Charlotte Götz. fig-cur.mp4 Videoclip showing results from the simulation defined by the input file, specifically three-dimensional current paths from different angles. @author : Jesper Lindkvist Email : [email protected] @author : Herbert Gunell Email : [email protected]

    Type Theory Unchained: Extending Agda with User-Defined Rewrite Rules

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    Dependently typed languages such as Coq and Agda can statically guarantee the correctness of our proofs and programs. To provide this guarantee, they restrict users to certain schemes a- such as strictly positive datatypes, complete case analysis, and well-founded induction a- that are known to be safe. However, these restrictions can be too strict, making programs and proofs harder to write than necessary. On a higher level, they also prevent us from imagining the different ways the language could be extended. In this paper I show how to extend a dependently typed language with user-defined higher-order non-linear rewrite rules. Rewrite rules are a form of equality reflection that is applied automatically by the typechecker. I have implemented rewrite rules as an extension to Agda, and I give six examples how to use them both to make proofs easier and to experiment with extensions of type theory. I also show how to make rewrite rules interact well with other features of Agda such as-equality, implicit arguments, data and record types, irrelevance, and universe level polymorphism. Thus rewrite rules break the chains on computation and put its power back into the hands of its rightful owner: Yours.Programming Language

    Multicenter study of the COPD-6 screening device: feasible for early detection of chronic obstructive pulmonary disease in primary care?

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    Peter Kjeldgaard,1 Jesper Lykkegaard,2 Heidi Spillemose,3 Charlotte Suppli Ulrik1,4 1Department of Respiratory Medicine, Hvidovre Hospital, Hvidovre, 2Research Unit of General Practice, University of Southern Denmark, Odense, 3General Practice Aarup Lægerne, Aarup, 4Institute of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark Background and aim: Early detection of COPD may reduce the future burden of the disease. We aimed to investigate whether prescreening with a COPD-6 screening device (measuring FEV1 and FEV6) facilitates early detection of COPD in primary care. Methods: In primary care, individuals at high risk of COPD (ie, age ≥35 years, relevant exposure, and at least one respiratory symptom) and no previous diagnosis of obstructive lung disease were examined with a COPD-6 screening device. In prioritized order, the criteria for proceeding to confirmatory spirometry were FEV1/FEV6 <0.7, FEV1 <80%pred, or clinical suspicion of COPD regardless of test result (medical doctor’s [MD] decision). Based on spirometry, including bronchodilator (BD) reversibility test, individuals were classified as COPD (post-BD FEV1/FVC <0.70), asthma (ΔFEV1 ≥0.50 L), or no obstructive lung disease.Results: A total of 2,990 subjects (54% men, mean age 59 years, and mean 28 pack-years) were enrolled, of whom 949 (32%) proceeded from COPD-6 screening to confirmative spirometry based on the following criteria: 510 (54%) FEV1/FEV6 <0.70, 382 (40%) FEV1 <80%pred, and 57 (6%) MD decision. Following confirmative spirometry, the 949 individuals were diagnosed as having COPD (51%), asthma (3%), and no obstructive lung disease (45%). COPD was diagnosed in 487 (16%) of the enrolled subjects in whom confirmative spirometry was performed in 69% based on FEV1/FEV6 <0.7 and in 29% based on FEV1 ≤80%pred.Conclusion: Prescreening with the COPD-6 device showed acceptable specificity for the selection of subjects for diagnostic spirometry and is likely to be a useful alternative to current practice in primary care. Keywords: early COPD, diagnosis, spirometry, general practice&nbsp

    35 frågor och svar inför en edering av Jesper Swedbergs Swensk Ordabok

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    In this paper, the author accounts for his work on editing an early 18th centurydictionary manuscript, bishop Jesper Swedberg’s Swensk Ordabok. A similar project– i.e. editing an old, hitherto unpublished dictionary manuscript – has beenperformed in Sweden only once before. This means that there is no tradition onwhich the solution of many problems concerning the edition of Swedberg'sdictionary could be based. For instance, there are no less than five manuscriptversions. Which of them should be selected as the basis manuscript of the edition,and to what extent should the differences between the manuscripts be accounted forin the edition? As argued by the author, none of the manuscripts written bySwedberg himself can serve as the basis manuscript, since they are all incomplete.Also, a relatively restricted account of the differences between the manuscripts issuggested; otherwise, the readability of the edition would be too low
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